The soundings made by the "Challenger" and "Gazelle" and the affinities which in certain respects exist between the islands, seem to point to the existence at one time of an extensive land area in this quarter, of which Kerguelen, Prince Edward's Islands, the Crozets, St Paul and Amsterdam are the remains.

"Challenger" (1874-1875) and those of the American vessels " Tuscarora " (1873-1876) and" Albatross " (1888-1892) may complete the tale.

" Challenger " (1873-1876), and the German ship " Gazelle " (1874-1876), the French expedition in the " Travailleur " (1880), and the U.S. surveying vessel " Blake " (1877 and later).

The cruises of the " Porcupine " and " Lightning," which led directly to the despatch of the " Challenger " expedition, were altogether within its " sphere of influence "; so also was the great Norwegian Atlantic expedition.

" Deep Sea Medusae," in Reports of the Challenger Expedition, Zool.

Actual or projected routes for telegraph cables across the deep sea have also been sounded with extreme accuracy in many cases; but beyond these lines of sounding the vast spaces of the ocean remain unplumbed save for the rare researches of scientific expeditions, such as those of the " Challenger," the " Valdivia," the " Albatross " and the " Scotia."

Watson, " Report on the Anatomy of the Spheniscidae," Challenger Reports, 1883.

The well-known Syllid, discovered during the voyage of the "Challenger," shows a modification of this form of budding.

C. M`Intosh, "Challenger" Reports (1885); E.

From 1879 to 1888 he was engaged on difficult experimental investigations, which began with an inquiry into the corrections required, owing to the great pressures to which the instruments had been subjected, in the readings of the thermometers employed by the "Challenger" expedition for observing deep-sea temperatures, and which were extended to include the compressibility of water, glass and mercury.

" Challenger " Expedit.

Hubrecht, " Challenger " Reports, xix.

Insane persons and persons under guardianship are excluded by the constitution, and " all persons convicted of bribery, perjury, larceny or of infamous crime, or who shall make or become directly or indirectly interested in any bet or wager the result of which shall depend upon any election," or who shall participate as principal, second or challenger in any duel, are excluded by legislative enactment.

The volume of theological tracts, again recast, was declined by two Basel publishers, Jean Frellon (at Calvin's instance) and Marrinus, but an edition Beza incorrectly makes Servetus the challenger, and the date 1534.

" Challenger " in1872-1876formed an epoch marking the end of the older order of things and the beginning of modern oceanography as a science of precision.

A second epoch comparable to that of the " Challenger " and resulting like it in a leap forward in the precision of the methods previously employed was marked by the institution in 1901 of the International Council for the Study of the Sea.

" Challenger " round the world says " of measured seas the Sardonian is the deepest with full under the scientific direction of Sir Wyville Thomson and the one thousand fathoms " (i.

Almost simulcentury and earlier, by which a lead thrown into the sea without taneously with the " Challenger," a German expedition in S.M.S.

3° E., on his return from his expedition to Spitseditorship of the " Challenger " Reports, Sir John Murray, has bergen.

Modern surveying ships no longer make use of hempen lines with enormously heavy sinkers, such as were employed on the " Challenger," but they sound instead with steel piano wire not more than 310 to 215 of an inch in diameter and a detachable lead seldom weighing more than 70 lb.

In 1876 the " Challenger " expedition found.

The existence of the latter, which extends to the African continent, was announced by Sir Wyville Thomson in 1876 as a result of his discussion of the deep-sea temperature observations of the " Challenger " expedition, though the fact was not confirmed by soundings until many years later.

The " Challenger " collections supplemented by those of other expeditions and of many telegraph and surveying-ships were studied in detail by Sir John Murray and Professor A.

The " Challenger " expedition found it on the Agulhas Bank, do the eastern coasts of Australia, Japan, South America and on the west coast of Portugal.

Red clay was discovered and named by Sir Wyville Thomson on the " Challenger " in 1873 when sounding in depths of 2700 fathoms on the way from the Canary Islands to St Thomas.

Red clay is the deposit peculiar to the abysmal area; 70 carefully investigated samples collected by the " Challenger " came from an average depth of 2730 fathoms, 97 specimens collected by the " Tuscarora " came from an average depth of 2860 fathoms, and 26 samples obtained by the " Albatross " in the Central Pacific came from an average depth of 2620 fathoms. Red clay has not yet been found in depths less than 2200 fathoms. The main ingredient of the deposit is a stiff clay which is plastic when fresh, but dries to a stony hardness.

The whole collection of 231 specimens of deep-sea deposits brought back by the " Challenger " shows the following general relationship: Proportion of Calcium Carbonate in Deep-Sea Deposits.

Radiolarian ooze was recognized as a distinct deposit and named by Sir ' John Murray on the " Challenger " expedition, but it may be viewed as red clay with an exceptionally large proportion of siliceous organic remains, especially those of the radiolarians which form part of the pelagic plankton.

The most numerous analyses have been carried out by Forchhammer, who dealt with 150 samples, and Dittmar, who made complete analyses of 77 samples obtained on the" Challenger"expedition.

Three types of areometer are in use: (I) the ordinary hydrometer of invariable weight with a direct reading scale, a set of from five to ten being necessary to cover the range of specific gravity from 1 000 to 1.031 so as to take account of sea-water of all possible salinities; (2) the " Challenger " type of areometer designed by J.

Buchanan on the " Challenger " it has been usual for British investigators to calculate specific gravities for sea-water at 60° F.

Buchanan found a mean of 20 experiments made by piezometers sunk in great depths on board the " Challenger " give a coefficient of compressibility K=491 X 107; but six of these experiments made at depths of from 2740 to 3125 fathoms gave K=480Xio 7.

Dittmar's analysis of the " Challenger " samples indicated an excess of oxygen in the surface water of high southern latitudes and a deficiency at depths below 50 fathoms.

Buchanan on the " Challenger " were vitiated by the incompleteness of the method employed, but they are none the less of value in showing clearly that the waters of the far south of the Indian Ocean are relatively rich in carbonic acid and the tropical areas deficient.

Buchanan from the " Challenger " observations.

Buchanan introduced an improved form on the " Challenger," also remaining closed by weight, the cylinder being very heavy and ground to fit the bevelled base-plate very accurately.

The observations made on the " Challenger " and " Gazelle," though enabling some perfectly sound general conclusions to be drawn, require to be supplemented.

Buchan's discussion of the two-hourly observations on the " Challenger " the total range between the daily maximum and minimum in the warmer seas is between o 7° and o 8° F., and for the colder seas still less (0.2° F.), compared with 3.2° F.

The effect of the Mediterranean water in the North Atlantic does not require such large figures to express it, but is none the less extraordinarily far-reaching, as first indicated by the work of the " Challenger " and subsequently defined by H.

The " Challenger " and other oceanographic expeditions have shown that on the bottom of the deep sea concretions of phosphate are now gathering around the dead bodies of fishes lying in the oozes; consequently the formation of the concretions may have been carried on simultaneously with the deposition of the strata in which they occur.

The " Challenger " discovered an area of radiolarian ooze between 7°-12° N.

That these animals were widely distributed in former times is proved by their occurrence at the present day in palaeozoic fossiliferous strata both of the northern hemisphere and of Australia; and despite the fact that their remains have not been found in rocks of the Mesozoic or Kainozoic epochs, it was conceived to be possible that living specimens might be dredged from the sea-floor during the exploration of the ocean depths undertaken by the "Challenger" expedition.

C. Haddon, "Report on the Polyplacophora," Challenger Reports.

Solutions were furnished by Wallis, Huygens, Wren and others; and Pascal published his own in the form of letters from Amos Dettonville (his assumed name as challenger) to Pierre de Carcavy.

He assisted Sir Wyville Thomson in the examination and classification of the collections of the "Challenger" exploring expedition, and wrote the Review of the Echini (2 vols., 1872-1874) in the reports.

Captain Cook visited the island in 1776, and, among other expeditions, the "Challenger" spent some time here, and its staff visited and surveyed various parts of it in January 1874.